The cold field emission from electrically conductive tips having tip radii in the nm range is being increasingly used for electronic components and displays.
For example, a cold cathode triode is known from W. G. Ornis et al, IEEE Trans. ED Vol. 36, Nov. 11, 1989, pages 2651-2657, incorporated herein. In the known component, a silicon tip that forms a cathode is arranged on a silicon wafer. A planar anode is arranged opposite the tip insulated from the cathode. A gate electrode is arranged at the level of the cathode annularly insulated from the cathode and from the anode. When a voltage having the size V.sub.AK is applied between the cathode (negative) and the anode (positive), then the cathode emits electrons at field strengths on the order of magnitude of 10.sup.7 V/cm. This field strength is proportional to V.sub.AK /r, where r is the tip radius of the cathode. This electron current can be controlled by applying a voltage to the gate electrode.
The rectifier effect of this component arises due to the different geometry of cathode (tip) and anode (plate). The emission field strength is therefore reached at the cathode at a significantly lower voltage V.sub.AK than at the planar anode.
Methods for manufacturing emitter tips are known from R. A. Lee et al, IEEE Trans. ED Vol. 36, Nov. 11, 1989, pages 2703-2708 and from R. N. Thomas et al, Solid St. Electr. 1974, Vol. 17, pages 155-163, both incorporated herein. For example, circular regions on an oxidized silicon wafer are thereby etched free with the assistance of a photolithography step such that an oxide spot remains in the middle of the circular region. The oxide spot remaining in the middle of the circle is subsequently undercut with the assistance of anisotropic or isotropic etching. Due to the crystalline structure of the silicon, a tip having corresponding side walls thereby arises, for example &lt;111&gt; or &lt;100&gt;. After the end of the undercutting, the oxide spots detach and the tip is exposed.
In this method, the tip geometry and thus the emissivity are influenced by local fluctuations of the etching rate given the simultaneous manufacture of a plurality of tips.